Closing and sealing of collapsible tubes



Dec. 21, 1937.

P. R. FECHHEIMER CLOSING AND SEALING OF COLLAPSIBLE TUBES 3 Sheets-Sheet1 Filed Feb. 12, 1934 INVENTOR.

M R. PM BY @flw/ v w N RN ATTORNEYS.

Dec. 21, 1937. P. R. FECHHEIMER CLOSING AND SEALING OF COLLAPSIBLE TUBES3 Sheets-Sheet 2 Filed Feb. 12, 1934 ATTORNEYS.

FEM/V72.

QZZQUYM Dec. 21, 1937. P. R. FECHHEIMER CLOSING AND SEALING OFCOLLAPSIBLE TUBES 3 Sheets-Sheet 3 Filed Feb. 12, 1934 III.

III

INVENTOR. ful R. BY

ATTORNEYS.

FIG. 8.

Patented Dec. 21, 1937 UNITED STATES 2,102,840 CLOSING am) same orcounrsmrn TUBES Cincinnati, Ohio, assignor Machine Company, Cincin- PaulR. Fechhehner, to The Karl Kiei'er nati, Ohio, a corporation of OhioApplication February 12, 1934, Serial No. 710,824

4 Claims.

My invention relates to methods of handling metal collapsible tubes ofthe kind for example,

in which tooth paste, creams and other viscous or liquid materials arepackaged and sold, and in particular it has to do with the method ofclosing and sealing such tubes, adapted to be carried on in connectionwith other operations thereon and resultingin the formation of animproved and more economical closure therefor.

One object of my invention is to provide a method of sealing collapsibletubes by welding to join the bottom edges of the tube, whereby economyof operation is effected. Hitherto it has been the general practiceafter the filling of a collapsible tube, which is done from the bottomthereof, to flatten the tube so that its bottom edges are contiguous andlie in parallel planes, and then to fold these edges over uponthemselves a plurality of times, afterward frequently holding the foldtogether by means of a clip of stiffer metal fastened thereto, or bylocking this. fold by means of a crimp or folding back, of the corners.These methods of sealing, while effective for most purposes, aresometimes uneconomical be-' cause they involve added cost, but moreimportantly, they do not provide a hermetic seal for the bottom of thetube. This becomes of importance, for example, where tubes containingliquefiable paste are shipped into warm or torrid climates, or arestored under elevated temperatures. Where the contents of the tubebecom'e liquefied, or where for any reason a pressure is built up insidethe tube, the contents are frequently forced outwardly through thebottom closure andserve to stain and destroy the appearance andserviceability of the tube itself, and of the wrappings or package inwhich it is contained.

invention, to provide for the sealing of the bottom of collapsible tubesso as to provide a liquid and gas tight joint in the nature of, ahermetic seal Still. another object of myinvention is to provide a meansand method for the continuous welding of the bottom edges of acollapsible tube which fits in well with the operations of filling andjuxtapositioning the bottom edges of the tube, whether this be done bycontinuous or step by step processes, but which is particularly adaptedto continuous processes of filling, closing and sealing.

These and other objects of' my invention, which will be set forthhereinafter, or will be apparent to one skilled in the art upon readingthese specifications, I accomplish by thatfserie's of process steps andby and in the constructions which I hereinafter disclose in exem'plaryembodiments. I Reference is made to the drawings, wherein:-

Figure 1 is a plan view of a closing and filling machine embodying myinvention.

Figure 2 is an elevational view thereof.

Figure 3 is a sectional view along the lines 33 of Figure 2. a

Figure 4 shows the bottom end of a tube sealed by welding, and the beadformed thereby.

Figure 5 is a view showing such a welded tube with its bottom folded ina simple fold.

Figure 6 is a side view of another stationary type of welding tool inits relation to the bottom of a tube.

Figure '7 is an end view'thereof.

Figure 8 is a view with parts in section of a typeof sealing device inwhichjuxtaposed rollers are employed.

Figure 9 is a partial sectional view of a type of sealing device inwhich a single rotatable roll is employed.

It will be understood that after the filling of a collapsible tube,which is usually done through the open bottom thereof, while the tube isin an inverted position, the bottom edges of the tube are'spread-so asto form a fish tail, and. so as to bring these bottom edges togetherfiatwise, so that they lie in parallel planes. They are then held inthis position by clamp members engaging the side walls of the tube fromeither side. The welding together of the juxtaposed bottom edges of thetube presents in practice, some serious problems. The metal of the tubeedges'is very thin and quitelikely to burn through. Thus, if heat wereapplied to the clamping members engaging the juxtaposed bottom edges,while a weld might be effected therebetween the tube walls have atendency to burn through at the edges of the heated members. I havefound, however, that it is possible to do'commercially successful andreliable, welding by the procedure hereinafter to be outlined in.detail. This procedure involves in the main, the clamping of the edgesof the bottom of the tube soas to hold these edges ,in juxtapositionedrelationship,- but in such a way as to leave these edges projecting ashort distance beyond the clamping means. If this is done and if theclamping means themselves are not relied upon to do the welding,successful welding can be carried on at the end of the tube in thatportion thereof which projects freely above the clamping devices. I havefound moreing in a continuous and progressive manner by starting with atool at one end of the juxtaposed edges and progressively forming a weldthere- 'along, finally reaching the other end of the juxtaposed edges.In other words, it is preferable, al-.

though not a limitation upon the broader aspects of. my invention, tocarry on the welding with a tool which has, practically speaking, apoint con-.

tact with the work, and by moving the work and the tool relatively toeach other during the prog- 'ress of the welding operation.

I have. illustrated in Figures 1 and 2, an-exemplary filling and closingmachinewhich hapbut is'clearly applicable to machines" having a step bystep motion, or to filling and closing operations which are carried onas separate steps or discontinuously. In the particular embodimentshown,the machine isbuilt up on a frame work I, upon which in a suitable tracka continuous chain indicated generally at 2, is caused to move.

This chain may comprise intermediate lengths 3, and holding means forcollapsible tubes indicated generally at 4. These holding means are morespecifically illustrated in Figure 3, where it will be seen that theycomprise a base member 4a., and a holder member 4b, slidably insertedtherein, and held by a set screw 5, operating in a slot 6 in the basemember 4a. The holder 411' is hollowed out as at "l and 8, to accept thetop' of a collapsible tube when the tube is in inserted position, andthe holder may likewise be provided with a kick-out device comprising'aplunger 9, and a spring l0, serving to hold the plunger in depressedposition. The base member do has ears thereon 40, which engage the trackmembers II onthe base I.

As shown, most clearly in Figures 2 and 6, the holder member 4b has aprojection 4d at its side, to which is attached a vertical rod I2. Thisrod bears at its upper end a pair of clamping jaws l3 and I4, hingedthereto, and urged to an outwardly extending or angular position asshown, by a spring member 15. I

At each end of thetable or frame I, I have shown sprocket members is andI I around which the chain 2 passes. -It' will be understood withoutfurther description, that these sprocket members, or one of them atleast, are suitably driven. "Empty collapsible tubes may be insertedinto the holders at the point-marked A on Figure 1. Abovethe sprocket 16there may be an automatic filling head it, fed with the plastic materialthrough a pipe i9, and bearing filling spout members 20. A particulardescription of this readily understood witliout further description,

and when so filled they pass from beneath the filling spouts and areacted upon by some device which spreads or ,fishtails' the bottom end.of the tube. I have shown an exemplary device for this purpose,consisting of a disc member 22, suitably mounted upon a driven shaft,and suitably timed by this shaft so that projections 23 on the disc,

75 enter the tops of the tubes and spread them sumover, that it ispreferable to carry on this weldr ciently so that the edges can bebrought into juxtaposition by the action of the clamp members l3 andDuring the further course of the progress of the tube, track members 23and 24 engage the clamp members i3 and I4 and bring them' together aboutthe flshtailed tube end. In this way the tubeedges are brought to lieagainst each other in parallel fiat planes. In Figure 3 it will be seen'how the clamping members [3 and I4, held together by the track members23 and 2 4, engage the end of the tube, and it will also be seen how afree portion of the tube ends projects above the clamping members l3 andpens to be of the continuous motion'type. My invention is not, however,limited to this type,

M, as at C.

The tube so disposed and held is caused to pass beneath a welding deviceof cylindrical form, indicated at 25, in Figures 1, 2 and 3-. Thismember is held above a suitable bracket 26. It is grooved as at 21 inthat portion of its surface which is to contact the juxtaposed edges ofthe tube bottom. "It is convenient to make the.

shown in Figure 2, that the welding member 25 may comprise an outercasing 25a, and an interiorally disposed electricheating'coil .28, and

; I have shown in Figures 1 and 3, means for an electrical connection tothis coil, indicated broad-' ly at 29. v

It will be understood however, that the way in which the welding memberis heated is not a limitation upon my invention. It is convenient andeconomical to use electrically heated members, but members otherwiseheated may be used as 'well as, in some instances, means for generatingelectric heat in the tube walls, or means for applying a flame thereto.Thus in Figure 7 one terminal of an electric circuit may be con-' nectedto the clamps l3. and I4 and the other to the tool 33. In the claimswhich follow, the term welding, unless modified by a specificlimitation, is to be understood as including any means for causinginterfusion of the top walls themselves. 3 It is also possible to addmetal to the Weld being made. One way in which this may be done is byfeeding solder, or the like, from a cup 55,: (Figure 6) attached to thetool, and in which the solder is maintained liquid by the heat of thetool. A passage 56, having an outlet 51 leads to the groove 37; but theoutlet is so restricted that the solder will not run out of it when thetool is not. in contact with the work.

Throughout the several views, I have indicated collapsible tubes beingworked upon broadly by the numeral 36. It will be noted that the machine.in Figures 1 to 3 illustrates a preferred method of operation in whichthe welding is carried on in a progressivemanner from 'one end of thetube bottom edges to the other end. I have found that more positiveresults can be secured more easily in this way. Figure 4 indicates thatthe welding operation preferably results in the production of a slightbeadoi consolidated' metal indicated at an. In Figure 5 I have shown at32 a simple fold produced in the metal of the tube end. This is by nomeans as complicated a fold as is ordinarily made, nor

does it take as much length of who. The head 2,102,840 in part serves tostiflen the bottom of the tube,.

but the fold is advisable for further stiflening, and also to take upthe lengths of the tube which extend between the clamping members l3 andI4, and the place where the welding is accomplished.

I have shown in Figures 6 and 7, another type of welding device whichcomprises a stationary block-like tool 33. This tool is hollowed outinternally as at 34, to accommodate a resistance heater 35, to whichconnection is made as at 36. The tool is likewise grooved as at 31,which grooving, as in the case of the first tool described, facilitatesthe welding operation, and the formation of a bead. The tool 33 may besupported by a bracket 38, in a. desired relationship to the work.

In Figures 8 and 9, I have shown exemplary types of rotativeweldingdevices. A rotative welding device while it is somewhat more complicatedto construct, has a certain advantage in that it can move with the workand present clean edges thereto during the progressive weldingoperation. 'Moreover, the rotation serves to carry away excess metal anddross. In Figure 8 a bracket 39 supports shafts 40 and it upon whichrollers 42 and 43 are mounted. These rollers are so positioned as tocontact only the upper edges of the tube bottom as shown. They, have theadvantage of forcing these edges more closely together, if necessary.The rollers may be hollowed and provided with electric heating elements44, and if so provided, they will likewise have slip rings 45 contactedby brushes 46, for the purpose of supplying electric current thereto. Itwill be clear that the rolls maybe driven if desired, or may be allowedto idle.

In Figure 9 I have shown a single roll 41 grooved as at l8, and mountedupon a horizantal shaft 49, in a bracket 50 above the work. This rolllikewise is provided with a heating element ii, and slip rings 52 whichare contacted by brushes 53 mounted on an insulating block 5| on thebracket. The operation of this structure will be clear without furtherdescription.

It will be understood that the embodiments of my invention which I havehereinabove described are exemplary only and that modifications may bemade in my invention without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patentis:-- 1 N 1. A method of sealing a metalliccollapsible tube-or like thin-walled container by interfusion, whichcomprises supporting juxtaposed wall portions in such a way that theedges thereof are free, bringing a heated tool into contact with saidedges so as to melt and interfuse said edges in an area adja nt saidtool, and moving said tool and said edges relative to each other so asto cause said area of molten metal to traverse said edges, the moltenmetal in said area forming by its surface tension a head ofsubstantially greater width than said juxtaposed edges, said head beingessentially located beyond any supporting means, the tube so sealedbeing shorter by substantially the amount of metal in said bead than thetube before sealing.

2. A method as set'forth in claim 1 in which wall portions of said tubeare juxtaposed by flattening said tube.

3. A method of sealing a metallic collapsible tube or like thin-walledcontainer by interfusion, which comprises juxtaposing the wall portionsto be welded and clamping said juxtaposed wall portions in such a waythat the edges thereof are free, bringing a heated tool into contactwith said edges so as to melt and interfuse said edges in an areaadjacent said tool, and moving said tool and said edges relative to eachother so as to cause said area of molten metal to traverse said edges,the molten ,metal in said area forming by its surface tension a bead ofsubstantially greater width than said juxtaposed edges, said a beadbeing located beyond the area of clamping pressure, the tube so sealedbeing shorter by substantially the amount of metal in said bead than thetube before sealing.

4. A method of,sealing a metallic collapsible tube or like thin-walledcontainer by interfusion of edge portions thereof, which comprisesflattening an end of said tube to bring the wall portions intojuxtaposition, clamping said wall portions between clamping membersso.as to leave an appreciable length of a juxtaposed edge portion ofsaid tube projecting therebeyond, bringing into contact with said edgeportions away from said clamping members a tool heated to a temperatureabove the fusion point of thematerial of said tube so as to melt saidmaterial in an area adjacent said tool and lying in part between saidtool and said clamping members but essentially out of contact with saidclamping members, and relatively moving said tube and tool so as tocause the area of molten metal to travel along said edge portions withand surrounding the contact of said tool with said tube,

the molten metal in said area forming by its surface tension a bead ofsubstantially greater width than said juxtaposed side walls, the tube sosealedv being shorter by; substantially the amount of metal in said beadthan the tube before sealing. 4

PAUL R. FECHHEIMER.

